航天器快速在线避障姿态规划控制

Fast Online Attitude Planning and Control for Spacecraft with Constraints of Collision Avoidance

考虑避障约束和姿态动力学约束,提出了一种利用Bezier曲线快速生成航天器三维运动角轨迹的方法,为更精确的轨迹优化控制工具提供了合适的初始近似。通过将Bezier方法获得的结果代入高斯伪谱方法(GPM)解算器中作为初始猜测,对Bezier方法获得的三维姿态运动轨迹的精度和性能进行评估。仿真结果表明,所提方法能在约10s内获得航天器的避障转移轨迹。将Bezier方法的结果作为初始值代入GPM后的结果表明,Bezier形函数的方法需要约1%的GPM计算时间就能得到性能指标仅相差约3%的姿态路径,因此,基于Bezier形函数的姿态路径规划方法非常适用于要求快速在线姿态规划的在轨服务任务。

Regarding the constrains of obstacle avoidance and attitude dynamics,the angular trajectory of the spacecraft is assumed to be generated by applying the Bezier curve for function. The boundary constraints and equations of motion are satisfied simultaneously under a time-optimized performance index by optimizing the finite unknown coefficients,which define the shape of the Bezier curves that are used to approximate the generic state variables,and the maximum control moment constraints and trajectory constraints of obstacle areas are considered. The simulation results demonstrate that the presented approach can be used to rapidly design the angular trajectory of the satellite under the dynamics and geometrics constraints by comparing with Gauss pseudospectral method( GPM) in the simulation. The results show that 1% GPM computation time required by applying Bezier method can be used to obtain the manipulator angle trajectory with perform-ance index of approximately 3%difference of the total transfer time spent. The presented method is suitable for on-orbit service( OOS) missions,which require a space manipulator to move to a certain position in a limited computation time.